Drying process

Abstract

A process for drying a water-wet mixture of materials, at least one of which is hydratable, which allows the mixture to be easily formed into the desired size and shape and easily and safely dried.

What is claimed is: 
     
       1. A process for drying a mixture of materials comprising: A. forming a water-wet mixture of a hydratable material and a nonhydratable material at a temperature which is higher than the temperature of hydration of the hydratable material;   B. forming the mixture of (A) into smaller units of the desired size and shape;   C. decreasing the temperature of the units of (B) to a temperature which is at or below the hydration temperature of the hydratable material; and   D. drying the units of (C) at a temperature high enough to remove the amount of free water and water of hydration which is desired but not high enough to cause the units to soften and stick together.   
     
     
       2. A process according to claim 1 wherein the hydratable material is selected from the group consisting of sodium sulfate, calcium bromide, ferric bromide, ferric chloride. ferric nitrate, lithium bromide, sodium acetate, sodium arsenate, sodium perborate, sodium phosphite, sodium acid phosphite and stannous chloride. 
     
     
       3. A process according to claim 2 wherein the nonhydratable material is a normally solid peroxyacid compound. 
     
     
       4. A process according to claim 3 wherein the hydratable material is sodium sulfate. 
     
     
       5. A process according to claim 4 wherein the peroxyacid compound is selected from the group consisting of diperdodecanedioic acid and diperazelaic acid. 
     
     
       6. A process according to claim 5 wherein an exotherm control agent is included in the mixture of (A). 
     
     
       7. A process according to claim 6 wherein the temperature of (C) is equal to or less than 90° F and the temperature of (D) is less than 130° F.